1. Field of the Invention
The present invention relates to a double-frame type library apparatus having front and rear storage compartment frames, and more particularly to method and apparatus for conveying information media such as magnetic tape between storage compartments.
2. Description of the Relevant Art
As an example of double-frame type library apparatus, a cartridge magnetic tape apparatus has been disclosed in Japanese Patent Application Laid-open No. 6-111439. In this cartridge magnetic tape apparatus, storage compartments each for containing a cartridge accommodating a magnetic tape are disposed separately in the front storage compartment frame and the rear storage compartment frame opposing each other, and a conveying means for conveying a cartridge between storage compartments are provided.
The conveying means is composed of a grasping means formed as a pair of fingers and a conveying mechanism for conveying the grasping means in the X-Y direction and the Z direction orthogonal to the X-Y direction. The conveying mechanism is disposed between the opposing storage compartment frames. The grasping means is composed of a plate member in a nearly T-form having a pair of fingers disposed mutually opposing in the Y direction and extending in the Z direction, and as the fingers approach/depart to/from each other by a driving mechanism, the cartridge is grasped or released.
In such conventional cartridge magnetic tape apparatus, for example, the cartridge taken out of the front storage compartment frame by the grasping means can be directly conveyed and stored into the rear storage compartment frame. However, the number of cartridges that can be conveyed at once is limited to one, and when exchanging cartridges between the front storage compartment frame and rear storage compartment frame, the following complicated process is needed. That is, the grasping means is conveyed into a desired first storage compartment in the front storage compartment frame, the cartridge taken out of the first storage compartment is once put temporarily in another storage compartment, and the other cartridge taken out from a desired second storage compartment in the rear storage compartment frame is put in the first storage compartment. Further, the cartridge temporarily put in the other storage compartment is taken out and put into the second storage compartment.
In such conventional cartridge magnetic tape apparatus, to enhance the speed in the exchange process, two sets of such conveying mechanism having the grasping means in the above constitution are required, and the number of constituent parts in the apparatus is increased.